Loading...
HomeMy WebLinkAbout20210513 Ver 1_More Info Received_20210624P TIMMONS GROUP Raieigu2 F Raleigh, NC 27607 www.timmons.com June 24, 2021 Chris Hopper U.S. Army Corps of Engineers — Wilmington District Raleigh Regulatory Field Office 3331 Heritage Trade Drive, Suite 105 Wake Forest, North Carolina 27587 Sue Homewood NCDEQ — Division of Water Resources 450 W. Hanes Mill Road, Suite 300 Winston-Salem NC 27105 Re: Response to Requests for Additional Information Wexford SAW-2020-01531 (Approx. 79.8 acres) Alamance County, North Carolina Dear Mr. Hopper and Ms. Homewood, On behalf of Eastwood Homes, we are providing a response to the Request for Additional Information (RAI) emails received on June 1 and 2, 2021 for Wexford, an approximately 79.8-acre site located at approximately 1031 Gibsonville Ossipee Road in Elon, Alamance County, North Carolina (the Site). The revised Impacts Maps have been attached showing details of stream protection measures for proposed Stream Impact 1, adjustments to Wetland Impact 2, and temporary impacts associated with retaining wall construction. The addition of a temporary wetland impacts from retaining wall construction has added 0.071- acres of temporary wetland impacts. In addition, 201-sq.ft. of permanent wetland impacts have been added in association with Wetland Impact 2 in order to reduce culvert burial and ensure up and down -slope connectivity. Due to the change in wetland impacts, an updated wetland impacts table is included below (PCN Section D, 2). All other impact amounts remain the same as reported in the Pre -Construction Notification (PCN) application dated 04/30/2021. The comments are outlined below in italics and are grouped by impact, with USACE comments in blue and DWR comments in green. Our response is below each comment. 1) How would the stream in Impact Area 1 be protected during construction? Similar projects often utilize a stream pump -around or similar measure to protect downstream areas from sedimentation during construction. The stream located at Impact Location 1 will be protected during construction with the installation of a temporary coffer dam on the upstream side of the proposed crossing to pump water around the open cut area to the downstream side. Plan details for the coffer dam can be found on Sheet No. CWI-1.8. 2) Impact Area 2 — similar concern. The proposed culvert would be buried approximately 1 foot below the existing grade within a wetland and at a 4.77 percent slope. Riprap proposed at the outlet of this culvert is presumably proposed to abate anticipated scour. We are concerned about preserving soil hydrology within the upslope wetland. Please address these concerns, and be aware that offsetting indirect ENGINEERING I DESIGN I TECHNOLOGY impacts may be required for all upslope wetland areas. Also please note the north arrow may bt incorrect on the impact detail. The existing grade as surveyed at the location of Wetland Impact 2 depicts a "hump" at the upslope side of the culvert, resulting from a previously -used logging road (Sheet No. CWI-1.5). To accommodate the existing grade at this location, while maintaining connectivity between the wetland up- and downslope of the proposed crossing, it was originally proposed that the culvert at Wetland Impact 2 be buried to a depth of 12-inches with a 4.77% slope. To accommodate the existing grade at the location of Wetland Impact 2, while also reducing possible wetland scour at the culvert outlet, and reducing potential impacts and loss of soil hydrology upslope of the crossing, the plans have been revised to propose additional grading upslope of the culvert inlet (Sheet No. CQI-1.5). This proposed grading will level out the "hump" upstream of the invert, eliminating the need for culvert burial into the wetland while also reducing the potential for wetland scour downstream by decreasing the culvert slope from 4.77% to 3.54%. The additional grading at Wetland Impact 2 will increase total proposed permanent wetland impacts from 2,866-sq.ft. (0.07-ac.) to 3,067-sq.ft. (0.07-ac.). Although impacts have increased slightly, the new design better enables wetland connectivity, overall preservation of the larger wetland area, and the stability of the crossing. Mitigation thresholds for the proposed project have not been reached with the additional proposed wetland impacts and mitigation for impacts to jurisdictional wetlands is therefore, not proposed. An updated wetland impacts table (PCN Section D, 2) is included below under item 3. The North Arrow on Sheet No. CWI-1.5 has been corrected. Similar to Impact Location 1, Impact Location 2 will be protected during construction with the installation of a temporary coffer dam on the up -slope side of the proposed crossing to pump water around the open cut area to the downstream side (if water present). 3) Lots north of Impact Area 2 (refer to Overall Impact Map 2 (CWI-I.2) appear to show irregular fill slopes abutting the wetland edge, and bold lines that may indicate retaining wall (?) impacts within wetlands. Please provide additional detail to document no impact would result in these areas, including any permanent or temporary measures proposed to inform construction activities onsite. The referenced bold lines indicate the presence of retaining walls. It is anticipated that retaining wall installation will required 10-ft of temporary impact area immediately adjacent to each wall installation during construction (see Sheet No. CWI-1.7). While the previously proposed project plans did not propose temporary wetland impacts, the addition of these four temporary impact locations in the revised plans will require a total of 0.071-acres (3,106-sq.ft.) of temporary wetland impacts (see Sheet No. CWI-1.3). Prior to the start of work, the contractor shall have all materials and equipment on -site to ensure temporary impacts to wetland features occur over the minimum time necessary. Hardwood mats will be placed over wetland areas and equipment movement within these areas will be kept to the minimum amount required. Immediately following construction, temporary wetland impact areas will be stabilized and reseeded using an appropriate riparian seed mix. Temporary wetland impact restoration notes have been added to the proposed site plans (see Sheet No. CWI-1.7). An updated wetland impacts table (PCN Section D, 2) is included below: Site Impact Type of Wetland Type of Impact # Reason Type Wetland Name Forested Jurisdiction Area (ac.) 2 Roadway Fill and P Headwater E Yes Corps 0.065 Riprap Forest 2 Residential P Headwater E Yes Corps 0.005 Development Fill Forest 3 Residential P Headwater J Yes DWR 0.011 Development Fill Forest 4 Residential T Headwater E Yes Corps 0.026 Development Fill Forest 5 Residential T Headwater E Yes Corps 0.016 Development Fill Forest 6 Residential T Headwater C Yes Corps 0.011 Development Fill Forest 7 Residential T Headwater B Yes Corps 0.019 Development Fill Forest 4) We have revised our standard "culvert burial' requirement for pipes on steep slopes and to prevent the risk of causing headcuts in the channel we request that if the culvert slope cannot reasonably be reduced then the culvert be installed "atgrade". Please see Condition 11 in the GC4256 as an example. Please revise the plans accordingly and submit new plan sheets (only pages with changes please). The plans have been revised accordingly reducing the slope from 3.22% to 2.54%. The updated plans can be found on Sheet No. CWI-1.4. Please review the updated Impact Maps and contact Matt Michel at (574) 514-3115 or matt.michelp_timmons.com if additional information is required. Sincerely, Timmons Group Sydni Law, WPIT Environmental Scientist 'Matt Mi hel, PWS., PhD Senior Environmental Scientist m m m bInOD O > ON A noo 3ON—% N— 0V-33d ISSO]-ANO—D O F O NOISIA42iOJX3M =iaffs.bii56b.9986i6 N46alen I a131 d o Ob J S N O W W I 1 oJ[09[z 9M�z0ia"'' n5 'Deon AliuiiWIT, -• 33I910 H9131tlL SyDO H9DOHF143A31HOtl nDOA • ]HI 038 —d 9N1A— S1H1 •� 0 uj W N z w0=� w z 06 p .OWQ �� o cor- Xco < z W m Zp8IM 0� DOS L.L Ci N r YOU~0 Nw aoz U Q B >oaoQ�uO zQ zz0 No m �oF, M, na mom rn ui F- z N p z Q z O W J z Q N n o p J Q J Op J z H Lu N O~ O w w ~_ w W Z ao W Z � o _ W ++ Zp` DOmam DpW Q (n U L.L Of O Q t QQO�00 0 a -< U O o a H Z N r�arw�w v<w�o� Q� '^ J �pamQz?om�>zJp Cu °oc�N�O vJ Q zDpjo�o--U)LwC=UO m r-z2U)of U Q-' z0aIrNw 0wIrWJFw� Q Ow Q uiO�OZo��?co=w W J-at] Q J w a CO Wm0HU) dZOHd W < U)LU W O � Q U o �I>L��� Q z c�i ri v u i a Q> -i d Z o QQQQQ C ry t 00000 — O 00000 N H H H H H J z 0z Z D L W O XZ U I 11 1 O z 1 W � I 1 1 ZJ __ 1 Q J ` w1-------- ' 1 1 1 1 aIL 1 1 1 1 1 9 ' 3 � 1 a O1 1 H � Y � J W W Q O O z � a a a � Q Q Q a M � � Q Q Q � W a Q z w�� �S U a H W a a J - a p � w� Q J Q L U � fA Op Q Q W J (7 z z� Q � H J W W W � O W in (Y � X Q J Z Z > Z � Z W W � !r !r W W !r O w w w a O � N M V L(7 Co I� W y 0 0 0 0 0 0 0 0 0 I IDb�/\V JIVV111UN VJ :JN 11J1X� y o o\ o%� q � f� o DN ALNf10D 3DN%a�O���3�SS03T1I�NOS9ID O p f U wO'9N46�abz6ixYf i5Albiu9iiW6631 0[Z lI1 1T y0 90N63Jtl N01SI60A • • d n O b J S N O W W 1133-0 H0 33i iv aea dd 9NI-0 Sr3ik.•� _=�_=319/:�4ilrll 11\ 6�pp// /,a g?/;//�� �-Z9- �= � � `\1'�nlr(/�/ o a o 0 _ W (/ M ' W coAW\\,.o///f '�rj''/�O ///// / //IIIII\ I \ \�`\ - y i• eIf l // \l III///I III,L J \ \\: _ . • • / -^ _- i I >�11/ //; 'll ll Il1 I I / / 1 1 \ \\\\ \\\\ \ , c-r_ o 1Ilf/ \\`\ ,\`�\\\\"`` \\-- - £�\ l `, _ (I._y .\ rr / !I ril ; \\I\IS Z:: ,\ 7✓f � �-^�� I'le\�`i;\\```r-O �,' 'tl°,\,111 r� III,/�/�/s�,9 , II j11 �oI�\I 1r _`�\ tl�,, t`,\)lY �l` ~`��(O„!e �(/� .,,�t(4, 1) t111 III /(//' �/il \� // III III`\�,\�\I\f�= ;o 2. I , fI1 \�.•l. ``�1.\1111;`ro� `�-,~ ��,l�i\�,II'11l\I1'/'Il, ;/,//,!(\-; \ �,/. `,I\ ("r ,It r+ . -. _6 ,. `1 w \�\° + I I //jl I I i \11tZ4 11\\�\\^.. N j,\•� P\`tl+III I I' \I \ It '%.,�=0�.,\\\\\ III\��\\' Q, .^=-s .- \ ```;: 'L, > i•i frf'l,!\11l r`,\\\ /\\\\\l Y/ r/ffl, wf/>r _ U J�_ry\- t<J' > 14firiQJI '^ o= _ .r \ `.Yl\z..�=•-�� r`� =r \\,111\ a�\.,r-°r �.�w 3r ,j � ,`\ `\ \, \ \O\,\ 65tiv d ) t)� /C � .. � r ° �°°• •--, /ram � - , �, \ lI I \ �`�\� O\ ,� l i \°? _ Y o�>>s>�/•L,L i` � -i�� "�:�� cr�� � �� - :�\\�\\ \-r ///l/ley'/; -. \\\ \\�\\\,\\\\r �.o'�%-'��I- \\• i �\�'ai`` a:y\ WY _- _ =Kati;\, i: \I'�•— \\,,�(�h.\\\\IIIIII Illith:��"_ �\ ,)i)1 .'° \•• '' S09' / \ . t• I , �� . _ ai •O . i J \ I , , \ ,1I1 1 U\ \ I I 1 / / 5h •/ _ M1r' 5,05�9��'�`r\'~77,- _jF ,- �riy 0S9� r'JIt�i\ /i S..J -r i✓� $�r/i/ S9y I \ ul li�l�\��'�o��t`>`�\\.�t\V<rr f5a �'r�?f-�=fir ,9 x\=099 a Q\ o9,14„ �\Il)11`III+1/1111� il4 f).�:a'� `y �B' f// !r ,ID,l 1 -- {4� /l�f c ,l. 7 r , % it - s • .. . \ \ . \ 1 \ J' l�`� >' f ?; hNN` N hrlll)r\ yti\<_ 1 `' •o r l r _ �99� ` ; �I 999 =- a t \pe \ \ 1 I it) ��tl\`\\®\\\ 1 4\ II\l\\\\`:'�•F _ kl �� ` .�` I'Ili//� Jam'-, IIIIII)f l/ , 45//J, I 1 14 1 1 11 \ \ _ . // \` ,li �� .Ss ` I ' 1';\��,``�'1'I1, IIIII I�,/,/r/1 / -r/I rl�iJ J, (p 111 ♦I I / 1 II/ II I I //i , / I T \ll �1 / \ Ai / ,�, � III'(/";//� /; \559- Cam= %r �\X�VAll0 NAII`' ` '/'/�11�r�AVA 11\ SIDVdWI VAVI2lS'8 aNt»13M 7Vt J•,°w.,°,,,.�°m,„,,.,.,w.° ww 3n0 � ry NOISIALEI ON ALNI100 --- N— XV- —SSO ]-ANO—D MdO w 11 111T a y, i56b 998 6i6131 d n O b J S N O W W 11 33I910 H91— SyH0 H9HOHF143A31HOtl LfIOA • 3H11tl 038 —d —I— SIH1 • � � coo _ � \��\\\\ ♦ \"\. yam.- _ ,I \ \ / = .� _ _ \� e z c 3z, 6f /r U O a� w Y 30 % U o is w a w z W o ii 3iC w z- a } z o 3C7 /l �,yvr \ 0 a < D c~ F-- o � w � // / / ! � m //!I/ Ill II Q z z < o // \L\ - ( r I a a a w w I¢ v ' �Q . /�`Y r r / /i / / y // l // //I I I III\\I Iw w w O • • rn z III w z of z cr `° `° z z o =_•`-'Arl tq/I z w z w w w z z Q O Q O z Z Q Q 71a\\��''1�.���<\ %� ,,,/rri/i / yh\ \�. ��\i= •� z w w w w r � \ I /;1) \\\ \ \ \ rr �!°' �l l' •�'\ Q _ I e / l / s I 111 1 1 I I //, / I /I /III / L �� =_\� �'\ ,i' j _�/J,I� 1 1 r j w rn �� \ \Ltyl cl \��\��\ \ \\III�III �r w \\ \\\ \ \ co )\ J o \l"`\ `\ _ i / I I I r \ 1 IIII� / � �-�, �� �,• N%_ ,, 1\,.\\0`�,_/1 I,II//r'�/r ���.: ,ILA ,-_== cl Lu 4 A. ion cl p1jLLtl�1\ \\�\��\ o :� ,\•� II -�`:'�"•`� \Y\ , \11\\\\\ \® \� \\\\ ' \\ ` \\ \\\ \ \�1'11 II IL♦\`\�`•_� _.— �t'W fC�\T�IJ\�re i as � r! 1, 111//, / rr0 r,, , r r _ II Jll / '� � "'�'i /'�/liI—=,—�\�•�„m.` 1 411P1\I\� �. 11 ICI"�"',h i r I rr,''/ ,u�/i/r�/, �— � �\\ \ 1 / r/, t-;%���4`:___cti�-•@°,,,�•+ v`\ � ' % I//ii , h II 1 'N4lr/r////r �� K\�`�,1///�/ I,gr��.^IIIi II '. `\_ \_e IIIIIII II'I/r 1 /, ! 1/rnl /, 1� ,1, L ,:'\///r rf//;'/�/ llrli„1 L 1 •1\I I 1 \\�\\` ``.�� �%_ _� `�` j S-- � _ `_ �` \\I\\\ \\\\11`/IIIII/,\L \ _ 'rri "'III - I//' - � ♦\` \\�� rr%� _ _ ;� ==_r-- -�_ _�_� \\\� IIL\\\� \J\ = ril l' III \ _ - �r'n,/ ''' L` \ _ �\ •t1d W I,o.o�. 3�0VI lDVAVI2lS CINV CINt»13M o ON AL non ]-- N— XV- M ISSO ]-ANO—DMdOJp N U mo ' i N =la�f a" y, L5-1.86i6131 d n O b J S N O W W I 1 of [09[z 9N M46�al 1 I z0i'ITI TA11' ITT -• 33I910 H9131tlL -y60 H940NF163A3IHJtl 01SI6 —A• 3N11tl O38 —d 9N1 A— S1H1 • � a 'v _o e N 6i 3ia 3 C7 Co Y G � w ¢ — o 0 N z Q w� o \ Q m m £ yh 3-Id02id Nt/�d 'Q IDVdWI - W1N3WNO2JIAN3 m o w ti u El ON 'A noo 3ON%WVl%'N— 0V-33d ISSO]-ANO—D I 42iO�X3M b9.6i6 xYf i56b.998.6i6131 oJ[09[Z 9M46�alI IIz0i al!n5 'Deon Aliui0lb5 Ne11 il SyDO H9DOHF143A31HOtl nDOA NOISIA •• -• 33I910 Ho13ltlL 3H11tl 03N —d—N A—SIH1 • d n O b J S N O W W I 1 CI 'G O O } O O co + a e o " ro 3 tC c� ui w o O J O— + LL �0 •• LL LLJ W QQ O U z ll�w O> z O a OJ m U W +o W w 0 a} 0 z w 0 z w a a U Of F F F m 0 w F cn cn 0 a a s 0 0 Q z Q o a z � ao Q Q Q Q v M 0 O W W W z Co _ W o � o w Z K Z Of m m Z Z z K z of W W z Z N z z 0 0 of� of� NN NN of of LO O J a F a F a a �1N0 I NI U o+ « 5 n e = C N a �O .ems w °°o ,•o w c w ° J UU)IU Eew o c °on ° a° N m N� �� C a° c o a3a `w3 woo:c rn moo. = CL N JD> y w'a N=y ��'gc `o o c m° O J = 3 e to a, a 'm z O �. w «ae �. o o'0 3 0 0 "z o c m Y w N o o =. N o o 3 o NDi N Q o a G O N« O D w O 13 C O C ° ovo�aaCoN�ow"o` o ao o Oa !r Fd cn O L z 'U / Q + / W n O 'O2/AWN! N!r N J X �Q �l l -.U� Ravi/�/�<21/ U w O VJ Q _ — W _ _ Ln 0 Xx ` O Q U Q (U I O> c~iLL� aQ- ��\ --o J= i i N0 J ' -`� o — Z z — _ l O \ 4 O O W - a 2 z� 1 �f `l �<�� o w - _- u)- 0 o cn o cn o cNo cNo Z o o coo coo z Q J � J >Q (Y ao Jo'N ZW G609 �v dU / X� � W (7 OS bZ9 9 809 l Q a a Q a c7 c� J � 6 S09 O zQ a ?� Q w L(7 Co O � � L(7 O O O L(7 Co O � o cn o cn o cn o � � Zl lZ9 a0 � O'9l9 90 SZ9 6'Ol9 O U � lS Z£9 Z'OZ9 zo X o cn o n El w o cn O L(7 O L(7 V Co Co Co (� Co Co Z H � � W (7 ZS Ll9 � O'Zl9 o� O (Y a L9 8l9 £L09 U !r L8 OZ9 o cn o � cn v 1L09 Nt/�d w� 3-Id02id 'Q IDVdWI -WIN3WNO2JIAN3 o oN'—noo 3oN%wVl%'N— 0V-33dlSSo]-ANO—D m w 42iOJX3M b119.fIT ,, xYf i56b.998.6i6131 •• d n O b J S N O W W I IIIIIL oJ[09[Z 9NM46111 I I alln5' TAli-IWITI -• 33I910 Hoi3l" SynO H9HOHF143A31HOtl NOISIALfIOA • ]HI 038 —d 9NIA— SIH1 •� O a+ e � co co O S+ m a� o�J �a W � 3ia o J w oC7 + L.L LL �DO 0 �/11 O a a O ww •• N Q< O C) n/ N U) LL W p> LU � \J = z O O m U O J z � Y O W w�� LU a> p a w a C) � F F o m a a w O ¢ o o a s z z � � � � � v O a a W W, pf W a F w w z + — W W LL LL O Q ? ? m O Z K Z K m m Z Z H V1 Z K Z K W W Z Z Z Z a � a O O � � 0 K K N N of Cr Z W W W W o o W W z J LL F LL F M N a a O O O LO +U `° � W U) . _ y Ll LL U_ o$ix N oQ N� o a° a3a `w3 �coi �MN ON0w 2 =o = Q. �a 0 J= a wx NNc �.n o��c Q c Y m Q 3 =° W �I o "Z 0 E N« a o$ a v v a g a _ t�I-ZaLwIX / / m a,- z 1 oW z i- o / / �j-� /zzu) -f /I /'�l �,i�" F2- / I I /_ �/I / -� wm v U 0 j \ 'W^ `= r \ \ VJ /A t� VJ N 00 I /LLB wJ J \ \ V U a 00 N �O > / e / JI a¢a- ` \ \ \ ¢ �2 \ \ i v o owao -I\ �� 0 ++ ` Q W �n o �n o �n (7 z z_ Q J w Q i 6£ 9£9 o �s£s 1 Uhl ?w x � Q LL lb9 Q S'b£9 tr a_ Q � Q tr J Z � 8'Z£9 Q w �n rr o o �n o �n � O ? w Z£ 9£9 � Q Z'££9 tY W (7 a O U L'££9 O C a o �n M o �n Z W � � 69 8£9 w ❑ Q O tr U 9'L£9 rr U C Cfl M VNV-ld V£ IDVdWI -WIN3WNO2JIAN3 µ e ON AL non ]0N%WVl % N— 0V-33d ISSO ]-ANO—D m w ti 42iO�X3M " u w N I'3ia o H9'b xy, i56b 998 6i6131 d �1 O b J S N O W W I 1 oJ[09[Z 9..... l..I z0i al!n5 'DROn Al1,1WI -• 31I91°H9131tlL "no Hono-4321—NOISIA—A • ]HI 1tl038—dDNI4A—S1H1 •� s �o O �+ a� LD � a U U 3ia w oC7 L O fY o a Ln o z O z w m U Y a > �p a w a z C) C F F cn cn O m a a Oz w U 0 0 d d ¢ z z � � � ao a a a ¢ ¢ ¢ a F�, Df w w w,z a � � w O z K z K m m z z V1 z z w w z z z z w w w w o o w w /J \ QOQ a z a -\ gz� 1 ¢¢0 QLL «LO W o oo erne o��aON N `\� _/^//✓ I\\ U rn e° o w ev Y o as U c rn t .e oo wn'^wo E m ti a o c z z02 \ �\ o a ° E •c a o o c v c ^' U° w C w IX V m O V O O V 3 Nt»d L t, IDVdWI-WIN3WNO2JIn.,ow„o,,,.m,om,„,,.,.,w.00, WN3 m ^ oN'—noo 3oN%wVl%'N— 0V-33dlSSo]-ANO—D m w 42iOJX3M w ll I IT a' b xy, L56b 998'6L6131 d n O b J S N O W W I 1 oJ[09[Z 9..... l..I z0i'IT ' 1 T Al1,1WI -• 39I919 H9131tlL SynO H9HOHF143A31HOtl NOISIALfIOA • ]HI 1 038 —d 9NI4A— SlH1 •o L l , s o �o o � � O �+ a \ o re ^ } J I\ a U) zwz • i < 0 < 1 F�Frn� wwwm� o I —zmz � rn —www� z O Z a w 0 IQ U Y w w a > CO wZ OJ a w a F F F p 0 O' m d d O a a a a a a a F F af w wOf z a0 - o � z af z of>> z z N z K z K w z z Z w Z 0 K � K � �N NN of of of of za w w w w o o w w J d F d F m N d d r a o c `a o w e v a a tiA m a_ yEw«yw cwa� z w Ow 0v_ y Y W W a ° G wo S •. ++ ° N ° w `0`0a mEa= c°w3'° `a 3vEo3w o ° E c $ -0 Noo a.0N`aa >.w to .= �� w cvc ° n = 3•303 3° °E°�w° c i5w w o °y N ' c° 5 w w m n 0 me n23 oN>_^�_^w 3 �cNwZ'=No0$t3 -003«-0 w U eIVI 2*%m,wam-Wa«maIANu , �( _-n: - _� N : ` Md O X M ` � :� :-A ®� ]HI.� __ /:w �..� d n o v o S N O W N I I B. Eta - •! | \ § j■ j (§ \ . < •, <§ !§� ) ar /§\ \ $�, M-- N.` m! (k